diff --git a/src/ClickEncoder.cpp b/src/ClickEncoder.cpp
index 3684db3..e6660da 100644
--- a/src/ClickEncoder.cpp
+++ b/src/ClickEncoder.cpp
@@ -10,6 +10,12 @@
 // ----------------------------------------------------------------------------
 
 #include "ClickEncoder.h"
+#if defined(ESP8266)
+#define CLICK_ENCODER_ISR_ATTR IRAM_ATTR
+#else
+#define CLICK_ENCODER_ISR_ATTR
+#endif
+
 
 // ----------------------------------------------------------------------------
 // Button configuration (values for 1ms timer service calls)
@@ -112,7 +118,7 @@ AnalogButton::AnalogButton(int8_t BTN, int16_t rangeLow, int16_t rangeHigh) : Cl
 // ----------------------------------------------------------------------------
 // call this every 1 millisecond via timer ISR
 //
-void ClickEncoder::service(void)
+void CLICK_ENCODER_ISR_ATTR ClickEncoder::service(void)
 {
   bool moved = false;
 
@@ -299,7 +305,7 @@ ClickEncoder::Button ClickEncoder::getButton(void)
   return ret;
 }
 
-bool ClickEncoder::getPinState() {
+bool CLICK_ENCODER_ISR_ATTR ClickEncoder::getPinState() {
   bool pinState;
   if (analogInput) {
     int16_t pinValue = analogRead(pinBTN);
@@ -311,3 +317,4 @@ bool ClickEncoder::getPinState() {
 }
 
 #endif
+#undef CLICK_ENCODER_ISR_ATTR